The present invention relates to a fence standard. The invention has particular application to a fence standard for use with electrical fencing line.
Throughout the specification, discussion of the present invention will be made with reference to electrified fencing systems. However, it should be appreciated that many of the principles discussed may also be applied to aspects of non-electrified fencing systems, and the reference to electrified fencing systems should not be seen to be limiting.
Portable electric fencing is an important aspect of livestock and pasture management. It is often used for the purpose of animal containment to ensure that livestock do not graze in an undesired area, or to set up temporary enclosures for animals to prevent the animals from extensive roaming. Controlling the area of pasture grazed by livestock is an important element of sustainable farm practice, where managing pasture growth assists in maximising food supplies and reducing the amount of supplementary feed required.
On a regular basis, a farmer will partition off sections of the pasture to exclude or contain livestock in order to permit pasture to recover from grazing activity. Portable electric fencing systems allow this to be achieved relatively easily.
A portable electric fence consists of three key components; a conductive wire, an energiser, and one or more fence posts to carry the wire. The energiser is a source of power for supplying an electric current to the wire. To energise a portable electric fence, a farmer will typically use a portable energiser, although a portable electric fence can also be powered via connection to a nearby permanent electric fence. An animal or person coming into contact with the wire will receive an electric shock.
The fence posts support the electric wire along its length to hold it in an elevated position above the ground. Typically, pigtail fencing standards are used for this purpose in portable electric fencing systems, as these are relatively lightweight and are generally considered simple to transport and install. FIG. 1 shows a prior art pigtail fencing standard (generally indicated by arrow 1). The standard 1 includes a metal rod 2, which is twisted in a coil 3 at one end. The coil 3 is covered in a plastic sheath 4. The coil 3 carries an electric wire 5 and acts as an insulator so that contact with the standard 1 will not result in an electric shock or shorting to ground.
In operation, as the wire 5 is pulled though the coil 3 it wears against the plastic sheath 4. Eventually this contacts the metal rod 2 beneath the sheath 4 which shorts out the electric fence.
U.S. Pat. No. 2,899,487 discloses an insulator coil made of bent thermoplastic tubing which is subsequently attached to a metal stand. While such a structure may not short the fence in the case of the wire wearing through the insulator, wearing though a wall of the tube would create a significant mechanical weakness. Further, the need to bend the tubing to form the insulator limits the range of materials useful for its manufacture.
The traditional pigtail arrangement also has a number of usability issues. For example, the open end of the coil (see tail 6 of FIG. 1) catches on wires, and tangles with other standards during storage and transportation. Further, the angle between the sections of coil 3 where it bends back over (see point 7 of FIG. 1) creates another point on which objects may become caught.
U.S. Pat. No. 4,470,579 discloses a post in which insulator clips are moulded directly to the shaft of the post. However, while the traditional pigtail coil has usability issues, it is a generally elegant solution which farmers are familiar with using. As such, it is seen as desirable to refine and/or improve the pigtail design rather than replacing it with another type of wire support.
Referring to FIG. 1, the standard 1 typically includes a foot 8 which may be used by the user as a footrest to drive the standard 1 into the ground, and act as a stabiliser. This bent rod foot 8 is typically welded or crimped to the rod 2. Carrying this out, as well as the need to manufacture the foot separately, adds additional steps to the manufacturing process—adding complexity, time, and therefore cost.
The typical hooked shape of the foot 8 also adds an additional point at which the standard 1 may become tangled with other standards. This can be exaggerated by the foot becoming bent during use—particularly when attempting to drive the standard 1 into hard ground.
U.S. Pat. No. 4,470,579 also discloses a foot press having blades which cut into the ground, and act as fins to provide stability. Such blades would be less likely to tangle with other standards than foot 8 of FIG. 1. However, one common use of the foot of fence standards is to hold a fence wire down close to the ground to create a gateway for the passage of a vehicle or stock. The blades are unsuited to such a task—they are more likely to cause damage to the wire than retain it in position.
It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.
All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.
Throughout this specification, the word “comprise”, or variations thereof such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.